Impact of Tier Pitch Scaling on Heavy-Ion Sensitivity of 3-D NAND Flash Memories

In this work, we study the impact of tier pitch scaling, one of the key enablers for increasing density, on the heavy-ion sensitivity of 3-D NAND Flash memories using replacement gate (RG) technology and charge trap (CT) cells. Single-event-effect cross section increases more than proportionally to the reduction in tier pitch, primarily due to the reduction in stored charge. Heavy-ion-induced threshold voltage shifts causing the errors are analyzed and discussed, with implications for future generations of nonvolatile devices.